With the completion of the human genome project, we will shortly know all of the cytokines encoded within our genome. Indeed within the last few years, there have been reports of at least ten new cytokines. While this will provide us with our "deck of cards", it is also clear that surprises continue to emerge regarding the function of cytokines we thought we knew well. Therefore, a major remaining problem is the understanding of the in vivo role of all these cytokines. Our comprehension of how cytokines work in concert in the protection against pathogens and in the pathogenesis of immune-mediated disease remains limited. Furthermore, the role of cytokines in immune homeostasis, lymphocyte memory and peripheral tolerance are actively being investigated. Equally exciting is the emergence of new cytokine and anti-cytokine therapies that have been remarkable effective. For these reasons, we believe a meeting on cytokines will be very timely and likely to be well attended by academia and industry alike. Our goals in this meeting are to review information on the newest cytokines, to provide new insights on their function in host defense and disease pathogenesis, to discuss new findings related to cytokine signaling and structure and to present the latest information on how manipulation of cytokines can be used therapeutically.